Please verify for me that you are on beta 4.3.1 and not on 4.2.4 which is the latest version on wifi
You can check this on the updates page from the Home Screen
Please send a video of what you are experiencing to support@singularsound.com but there could be many reasons you are hearing distortion, you may be going in too loud into your playback device!
Include all the information you can about your setup and what you are trying to accomplish
Thanks for reporting
This is fixed in 4.3.1